Three-phase power supplies are utilized for various high-power applications, including, but not limited to, industrial and/or communication systems. Three-phase power is a common form of electrical power and a popular method of electric power transmission and distribution. This is mainly due to its inherent benefits for high power transmission and its smooth wave form quality which allow three-phase electrical equipment to run smoothly and last longer. A three-phase system is generally more economical than others because it uses less conductor material to transmit electric power than an equivalent single-phase or two-phase system operating at the same voltage.
Typically, a high voltage flyback converter can be utilized for alternate current (AC) to direct current (DC) or DC to DC power conversion. Specifically, the flyback converter provides galvanic isolation between the input and any outputs. In general, the flyback converter can include a buck-boost converter with an inductor split to form a transformer, such that voltage ratios are multiplied with an additional advantage of isolation. However, the design of the high voltage flyback converter limits the efficiency, reliability, and power density of the converter and can complicate control of the converter. For example, in a discontinuous mode, high root mean square (RMS) and peak currents are observed in the design, and high flux excursions are detected in the inductor. In another example, in a continuous mode, a voltage feedback loop requires a lower bandwidth due to a right hand plane zero in the response of the converter, and a current feedback loop used in current mode control needs slope compensation in cases where the duty cycle is above fifty percent. Accordingly, the design of a three-phase auxiliary power supply is not trivial and typically includes expensive components. In addition, a three-phase main power supply unit provides very high DC voltage which exceeds a 400 Volt (V) DC limit the high voltage flyback converter can support.